Adjustable angle traction tester



Nov. 24, 1959 R. R. BARRON 2,913,896

ADJUSTABLE ANGLE TRACTION TESTER Filed Feb. 8, 1957 2 Sheets-Sheet J R Wad/ax,

ATTORNEY Edward; R. Barron.

Nov. 24, 1959 E. R. BARRON ADJUSTABLE ANGLE TRACTION TESTER 2 Sheets-Sheet 2 Filed Feb. 8, 1957 INVENTOR ATTORNEY United States Patent ADJUSTABLE ANGLE TRACTION TESTER Edward Robert Barron, Framingham, Mass., assignor to the United States of America as represented by the Seeretary of the Army Application February 8, 1957, Serial No. 639,129

4 Claims. (Cl. 73-9) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a traction testing device and has for it; primary object to provide an adjustable mechanism for measuring the maximum angle of inclination of traction which can be afforded by a given type of outsole and heel on a given type of terrain.

Another object of the invention consists in providing an adjustable mechanism for measuring the traction of outsole and heel on a particular terrain or two different terrains while the wearer of the shoes ascends and descends the pathways of the mechanism.

A further object of the invention resides in the provision of a testing mechanism provided with a pair of ramps or pathways and a connecting platform which may be vertically adjusted as a unit.

A still further object of the invention consists in providing adjustable ramps capable of receiving interchange able surfaces to simulate various types of terrain.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings, in which,

Figure 1 is a perspective view of the complete testing apparatus ready for use.

Figure 2 is a fragmentary plan view of the apparatus.

Figure 3 is a side elevational view of one of the supporting standards.

Figure 4 is a side elevational view of the apparatus, parts being broken away, and

Figure 5 is a detail vertical sectional view through the lower portion of the apparatus.

Referring to the drawings ingreater detail and by reference numerals, the numeral 1 indicates generally the vertical frame of the apparatus comprising the four posts 2 supported on base plates 3 and suitably braced in their rectangular arrangement by angle irons 4. The posts 2 are H-shaped in cross section and provide trackways 5 for the rollers 6 each mounted in a clevis or bracket 7 fixed to each side of the inner ends of the two ramps 8.

The ramps 8 are substantial duplicates and each comprises a floor portion provided with longitudinally-extending side flanges 9 and a partition 10 dividing the floor of the ramp into a tread-receiving portion 11 and an adjacent portion 12 to accommodate observers of any tests being carried out on the mechanism. The portion 11 may be provided with any preferred means 13 for securing in place on the surface 11 any type of tread or terrain 13 to be tested, and the passageway 12 is preferably provided with transverse cleats 14 to facilitate the passage of observers when the ramp is arranged at a substantial incline.

A hand rail 15 may be mounted on each side of each of the ramps 8, and the outer ends of the ramps are provided with rollers 16 which movably support the ramps on the ground and facilitate movement along the ground or other support as the ramps are .raised and lowered in a manner to be presently described. Pairs of pegs 17 for insertion in the series of holes 18 in a concrete or other base 19 serve to brace the ramps in their various adjusted positions. Also the ramps are preferably provided with clinometers 20 to automatically indicate the inclination of the ramp as it is raised or lowered.

The brackets 7 in which the rollers 6 are mounted are pivotally connected with a platform 21 which is disposed within the framework of the four posts 2 and is raised and lowered with the ramps. The mechanism for raising and lowering the ramps comprises cables 22 which have their free ends secured to the brackets 7 which are in turn secured to the ramps. The cables 22 are threaded over guide pulleys 23 mounted in the upper ends of the posts 2 and thence extend downwardly to the Windlass 24, there being one at each side of the mechanism for operating two cables as clearly indicated in Figure l. Crank arms 25 are provided for manual operation of the windlasses.

In order to insure definite positioning of the ramps for the various tests the posts.2 are provided with indicia 30 (Figure 3) showing the angle of the ramp for each vertical position of the inner end of the ramp along the post. Also, in order to insure the safety of the persons traversing the ramps 8 and the platform 21, when the ramps are in their uppermost positions (Figure 4), hand rails 31 are secured to the upper ends of the posts 2.

In the operation of the traction testing device, the material 13' to be used in the test, concrete, mud, turf or the like, is applied to one or both of the tread-receiving sections 11, or one type of material may be applied to one section and another type to the other section. The ramps may then be elevated to provide an inclination approximately that which the operator feels is about right for testing the particular material and the shoes having the particular outsoles and heels to be tested. The shoes are then placed on the feet of the persons taking part in the test and such persons then ascend one of the ramps and descent the other one under close observation of the persons conducting the tests. Depending upon the results of the first demonstration the ramps may be either raised or lowered and the tests repeated until all necessary data have been obtained as to the traction characteristics of the items being tested.

From the foregoing description taken in connection with the accompanying drawings'it will be apparent to those skilled in the art that I have devised a rather simple and inexpensive construction of traction tester which may be operated without the use of skilled labor, that it provides for tests with various types of terrain, and that the items may be tested while the subject is walking both uphill and downhill.

In accordance with the patent laws I have described what I now consider to be the preferred form of the invention but inasmuch as various minor changes may be made in structural details without departing from the spirit of the invention and it is intended that all such changes be included within the scope of the appended claims.

I claim:

1. A traction testing mechanism comprising a vertical frame, a trackway extending along the frame, a vertically adjustable ramp having its inner end slidably mounted on the trackway, a base for supporting the opposite end of the ramp and means on the upper surface of the ramp for releasably securing thereon various types of tread surfaces, whereby the frictional characteristics of the various tread surfaces may be compared at various inclination angles.

2. A traction testing mechanism comprising a vertical frame, a vertically extending trackway formed of rails of substantially U-shaped cross section on the frame, a

ramp, rollers on one end of the ramp, said rollers being disposed on the trackway, means on the upper surface of the ramp for releasably securing thereon various types of tread surfaces and means connected with said one end of the ramp for raising and lowering the same,"whereby the frictional characteristics 'of the various tread surfaces may be compared at various inclination angles.

3. A fraction testing mechanism comprising a vertical frame, a vertically extending trackway on one side of the frame, aramp, rollers on one end of the ramp for cooperation with the trackway, means connected with said one end of the ramp for raising and lowering the same, said frame being provided with 'indicia for indicating in degrees the various angular positions of the ramp, and means on the upper surface of the ramp for releasably securing thereon various types of tread surfaces, whereby the frictional characteristics of the various tread surfaces may be compared at various inclination angles.

References Cited in the file of this patent UNITED STATES PATENTS 1,668,593 Jones May 8, 1928 1,772,415 Carpenter Aug. 5, 1930 1,795,405 Nash Mar. 10, 1931 FOREIGN PATENTS 383,685 Great Britain Nov. 24, 1932 

